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-rw-r--r--include/uapi/linux/rseq.h102
1 files changed, 58 insertions, 44 deletions
diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
index d620fa43756c..9a402fdb60e9 100644
--- a/include/uapi/linux/rseq.h
+++ b/include/uapi/linux/rseq.h
@@ -10,13 +10,8 @@
* Copyright (c) 2015-2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
-#ifdef __KERNEL__
-# include <linux/types.h>
-#else
-# include <stdint.h>
-#endif
-
-#include <linux/types_32_64.h>
+#include <linux/types.h>
+#include <asm/byteorder.h>
enum rseq_cpu_id_state {
RSEQ_CPU_ID_UNINITIALIZED = -1,
@@ -52,10 +47,10 @@ struct rseq_cs {
__u32 version;
/* enum rseq_cs_flags */
__u32 flags;
- LINUX_FIELD_u32_u64(start_ip);
+ __u64 start_ip;
/* Offset from start_ip. */
- LINUX_FIELD_u32_u64(post_commit_offset);
- LINUX_FIELD_u32_u64(abort_ip);
+ __u64 post_commit_offset;
+ __u64 abort_ip;
} __attribute__((aligned(4 * sizeof(__u64))));
/*
@@ -67,28 +62,30 @@ struct rseq_cs {
struct rseq {
/*
* Restartable sequences cpu_id_start field. Updated by the
- * kernel, and read by user-space with single-copy atomicity
- * semantics. Aligned on 32-bit. Always contains a value in the
- * range of possible CPUs, although the value may not be the
- * actual current CPU (e.g. if rseq is not initialized). This
- * CPU number value should always be compared against the value
- * of the cpu_id field before performing a rseq commit or
- * returning a value read from a data structure indexed using
- * the cpu_id_start value.
+ * kernel. Read by user-space with single-copy atomicity
+ * semantics. This field should only be read by the thread which
+ * registered this data structure. Aligned on 32-bit. Always
+ * contains a value in the range of possible CPUs, although the
+ * value may not be the actual current CPU (e.g. if rseq is not
+ * initialized). This CPU number value should always be compared
+ * against the value of the cpu_id field before performing a rseq
+ * commit or returning a value read from a data structure indexed
+ * using the cpu_id_start value.
*/
__u32 cpu_id_start;
/*
- * Restartable sequences cpu_id field. Updated by the kernel,
- * and read by user-space with single-copy atomicity semantics.
- * Aligned on 32-bit. Values RSEQ_CPU_ID_UNINITIALIZED and
- * RSEQ_CPU_ID_REGISTRATION_FAILED have a special semantic: the
- * former means "rseq uninitialized", and latter means "rseq
- * initialization failed". This value is meant to be read within
- * rseq critical sections and compared with the cpu_id_start
- * value previously read, before performing the commit instruction,
- * or read and compared with the cpu_id_start value before returning
- * a value loaded from a data structure indexed using the
- * cpu_id_start value.
+ * Restartable sequences cpu_id field. Updated by the kernel.
+ * Read by user-space with single-copy atomicity semantics. This
+ * field should only be read by the thread which registered this
+ * data structure. Aligned on 32-bit. Values
+ * RSEQ_CPU_ID_UNINITIALIZED and RSEQ_CPU_ID_REGISTRATION_FAILED
+ * have a special semantic: the former means "rseq uninitialized",
+ * and latter means "rseq initialization failed". This value is
+ * meant to be read within rseq critical sections and compared
+ * with the cpu_id_start value previously read, before performing
+ * the commit instruction, or read and compared with the
+ * cpu_id_start value before returning a value loaded from a data
+ * structure indexed using the cpu_id_start value.
*/
__u32 cpu_id;
/*
@@ -105,27 +102,44 @@ struct rseq {
* targeted by the rseq_cs. Also needs to be set to NULL by user-space
* before reclaiming memory that contains the targeted struct rseq_cs.
*
- * Read and set by the kernel with single-copy atomicity semantics.
- * Set by user-space with single-copy atomicity semantics. Aligned
- * on 64-bit.
+ * Read and set by the kernel. Set by user-space with single-copy
+ * atomicity semantics. This field should only be updated by the
+ * thread which registered this data structure. Aligned on 64-bit.
*/
- LINUX_FIELD_u32_u64(rseq_cs);
+ union {
+ __u64 ptr64;
+#ifdef __LP64__
+ __u64 ptr;
+#else
+ struct {
+#if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || defined(__BIG_ENDIAN)
+ __u32 padding; /* Initialized to zero. */
+ __u32 ptr32;
+#else /* LITTLE */
+ __u32 ptr32;
+ __u32 padding; /* Initialized to zero. */
+#endif /* ENDIAN */
+ } ptr;
+#endif
+ } rseq_cs;
+
/*
- * - RSEQ_DISABLE flag:
+ * Restartable sequences flags field.
+ *
+ * This field should only be updated by the thread which
+ * registered this data structure. Read by the kernel.
+ * Mainly used for single-stepping through rseq critical sections
+ * with debuggers.
*
- * Fallback fast-track flag for single-stepping.
- * Set by user-space if lack of progress is detected.
- * Cleared by user-space after rseq finish.
- * Read by the kernel.
* - RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT
- * Inhibit instruction sequence block restart and event
- * counter increment on preemption for this thread.
+ * Inhibit instruction sequence block restart on preemption
+ * for this thread.
* - RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL
- * Inhibit instruction sequence block restart and event
- * counter increment on signal delivery for this thread.
+ * Inhibit instruction sequence block restart on signal
+ * delivery for this thread.
* - RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE
- * Inhibit instruction sequence block restart and event
- * counter increment on migration for this thread.
+ * Inhibit instruction sequence block restart on migration for
+ * this thread.
*/
__u32 flags;
} __attribute__((aligned(4 * sizeof(__u64))));